GM TB injector questions, HELP!

[David Doddek]

Greg wrote:

>Well I finished my carb to TBI conversion on my 86 chevy 2.8l last night.  
>Double checked everything and turned the key hoping to hear the engine 
>spring to life.  But alas, it was not to be... so now I have questions!
>
>I put a DMM (I have a cheesy little Radio shack analog meter) on the 
>injector leads, cranked the starter and the meter seemed to move to about 2
Volts. 

This would be a normal voltage to see. as the are actually only on for a
short period of time at cranking or any other speed.  The only time you
would actually see 12 volts would be at full throttle at max revs.  And NO,
the volt meter does not integrate, it does an Average.

>I know that the injectors are pulse width modulated, and at start up I expected
>the reading to be closer to 12V.  Their is a high pulse width at start 
>up right?  the DMM should integrate the signal and show around 12V, right???
>
>The throttle body (w/ injectors) was purchased from a junkyard.  I
>hosed the thing off good with carb cleaner and put a rebuild kit in.  New
>seals and filter screens around the injectors.  Could the injector solenoid 
>be stuck?  How common is it for these injectors to go bad??
>
>I see no evidence of fuel being sprayed into the throttle body when
>I crank the starter, I don't smell it or see a trace of it.  Is it
>the injectors, or the computer...  HELP!!:)
>
>TIA as usual
>
>Greg Woods
>gwoods at symtx.com
>austin, tx
>
>
Injectors from junk yards tend to sit around a lot.  I have bought throttle
bodies before from the yards and had the injectors stuck.  Using very
carefull methods of pressing on the pintle tip or using a rod to press on
the injector disk.  Also make sure you are getting fuel pressure at the
injector.  For throttle body it should be around 17psi.

David Doddek     pantera at pobox.com    www.pobox.com/~pantera    217-422-3722
69 EFI Fairlane, 89 T-bird SC, 74 Twin turbo NOS EFI Pantera #6825
If you are going to go fast, go real fast.